1. Field of the Invention
The present invention generally relates to the processing of printed documents and, more particularly, systems and apparatus for creating, reproducing, disseminating and storing the information content of documents in both image form and in encoded symbol form.
2. Description of the Prior Art
In current times, more and more emphasis is being placed on the dissemination of information. While a vast amount of data and information is disseminated by electronic networks, such as computer networks, the full information content of such communications does not leave a lasting impression on the recipient. Only printed information in hard copy form that can be read, studied, and readily saved for future reference, is truly capable of leaving a lasting impression. Unfortunately, the dissemination of printed material is cumbersome and slow as compared to the electronic transfer of information and data, and further, once information is in printed form it is difficult to return the information and data to electronic form. Certainly, printed material, such as documents, can be machine scanned or imaged for conversion to electronic data which then can be readily transferred. However, such conversion and transfer are time consuming, susceptible to error, and often result in loss of portions of the original data content.
One commonly used approach for representing information in a highly convenient machine readable form is to encode the information into a pattern of indicia having elements of different reflectivity, such as the ubiquitous UPC bar code symbol. The bar code symbol is optically different reflectivity, such as the ubiquitous UPC bar code symbol. The bar code symbol is optically scanned and the resulting signals are decoded into data representing the symbol encoding. This data can then be readily entered into and processed by a data processing system. Typical bar code symbols, such as the UPC symbol, are one-dimensional in character and thus are extremely limited in amount of data that can be encoded therein.
In the above-cited copending application, application Ser. No. 07/461,881, a two-dimensional bar code symbol is disclosed, which has high information density and capacity capabilities, as well as error detection and correction features. This symbol, known as the PDF417 symbol, is capable of representing as many as 500 characters per square inch of ASCII dam. Thus, a relatively small number of PDF417 symbols, and in some cases a single PDF417 symbol, has the capacity to encode alphanumeric text filling a letter-size document.